Between different atmospheres, we observe that the solid haze analogues appear to incorporate certain molecules more readily than others. In Figure REF , we show Van Krevelen diagrams, which are widely used in the petroleonomics field and have since been used for Titan atmospheric haze studies [1]}. These diagrams help visualize classes of compounds, as these have characteristic elemental ratios, resulting in clustering of similar compounds in specific locations on a Van Krevelen diagram [2]}. We show two forms of this diagram. The first (top row of Figure REF ) compares H/C to N/O, which shows that distinct nitrogen-to-oxygen ratios form in all of our samples. The second (bottom row of Figure REF ) shows H/C vs O/C. We follow the ratio bounds of [3]} to map where carboxylic acids (fatty acids), unsaturated hydrocarbons, aromatic hydrocarbons, amino-acid-like compounds, and carbohydrates/sugars fall in this H/C vs O/C phase space. Distinct diagonal, vertical, and horizontal lines are visible in this phase space as well. Such lines form along characteristic H/C and O/C ratios, which are characteristic of particular reaction pathways, such as methylation or demethylation, oxidation or reduction, etc. [2]}.
